1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to a printing resist used as a patterning method of a liquid crystal display (LCD) device.
2. Discussion of the Related Art
In recent years, a variety of flat panel display devices have been developed that have an ultra-slim display screen with a thickness of several centimeters. In particular, liquid crystal display (LCD) devices are widely utilized in a variety of applications including notebook computers, monitors, spacecraft and aircraft, for example, owing to advantages such as low operation voltage, low power consumption and portability.
LCDs may include a first substrate and a second substrate, and a crystal liquid layer interposed between the first substrate and the second substrate.
The first substrate may include a plurality of gate lines and a plurality of data lines substantially perpendicular to the gate lines in order to define pixel regions. The first substrate may also include a plurality of thin film transistors (TFTs) each formed at a crossing between an associated one of the gate lines and an associated one of the data lines, and a plurality of pixel electrodes formed at respective pixel regions. Each pixel electrode is connected to an associated one of the thin film transistors.
The second substrate may also include a blocking layer for blocking light leakage from the gate lines, the data lines and the thin film transistors. The second substrate may also include color filter layers formed on the blocking layer and a common electrode formed on the color filter layers.
As mentioned above, the LCD device may include a variety of constituent components. Accordingly, the LCD device is produced through several processes. In particular, photolithography has been generally used to pattern each constituent component into various shapes.
FIGS. 1A to 1D are cross-sectional views schematically illustrating a related art photolithography process.
As shown in FIG. 1A, a pattern layer 20 and a photoresist layer 30 are sequentially formed on a substrate 10.
As shown in FIG. 1B, the photoresist layer 30 is subjected to light irradiation with a light irradiator through a mask 40 having a predetermined pattern.
As shown in FIG. 1C, the pattern layer 20 and the photoresist layer 30 are patterned by developing and etching processes.
As shown in FIG. 1D, the photoresist layer 30 is removed with a photoresist stripper, to form a final photoresist pattern.
Photolithography necessarily involves a photomask having a predetermined pattern, that disadvantageously results in an increase in production costs. In addition, photolithography involves a developing process, which leads to complex production and consumes a lot of time.
Accordingly, there has been a demand to develop a novel patterning method that solves the disadvantages of photolithography. To satisfy such a demand, a patterning method using a printing roll was suggested.
FIGS. 2A to 2D are sectional views schematically illustrating a related art patterning method using a printing roll.
As shown in FIG. 2A, a photoresist 30 is applied to a printing roll 60 equipped with a blanket 65 mounted on the surface thereof using a printing nozzle 50.
Since the blanket 65 mounted on the surface of the printing roll 60 is made of an elastic resin, it reduces the friction between the printing roll 60 and a printing plate (not shown), when the photoresist 30 applied to the printing roll 60 is transferred to the printing plate.
As shown in FIG. 2B, the printing roll 60 is rotated on the printing plate 70, where protrusions 75 are formed in a predetermined pattern, to transfer a partial photoresist 30b to the protrusions 75. As a result, the printing roll 60 is patterned by the remaining photoresist 30a. 
As shown in FIG. 2C, the printing roll 60 is rotated on a substrate 10 where a pattern layer 20 is formed, to transfer the photoresist 30a to the substrate 10.
As shown in FIG. 2D, the pattern layer 20 is etched using the photoresist 30a as a mask, followed by removing using a photoresist stripper, to form a photoresist pattern.
The photoresist 30a is used as a mask for etching the pattern layer in a patterning method using a printing roll as well as photolithography.
Since the photoresist characteristics change upon the introduction of light, the photoresist is applicable to photolithography. However, when the photoresist is employed in the patterning method using a printing roll, the solvent constituting the photoresist may permeate into the blanket. As a result, the blanket is swelling, whereby pattern defects may occur, thus making it impossible to realize a desired pattern.
Accordingly, there is an increased need to develop a novel resist capable of being used as a substitute for the photoresist in a patterning method using a printing roll.